gitlab_project_approval_rule is missing parameter 'applies_to_all_protected_branches'

Bug Report

Currently all branch ids have to be explicitly listed, i would like to instead apply the rule to all current and future protected branches via 'applies_to_all_protected_branches'.

The API supports it: https://docs.gitlab.com/ee/api/merge_request_approvals.html#create-project-level-rule

But it is missing in terraform

Relevant Terraform Configuration

# possible
resource "gitlab_project_approval_rule" "example-two" {
  project              = 5
  name                 = "Example Rule 2"
  approvals_required   = 3
  user_ids             = [50, 500]
  group_ids            = [51]
  protected_branch_ids = [gitlab_branch_protection.example.branch_protection_id]
}

# but i would like to do this

resource "gitlab_project_approval_rule" "example-two" {
  project              = 5
  name                 = "Example Rule 2"
  approvals_required   = 3
  user_ids             = [50, 500]
  group_ids            = [51]
  applies_to_all_protected_branches = true
}

Implementation Details

Implementing this will require adding a new applies_to_all_protected_branches attribute to the schema for the gitlab_project_approval_rule resource, which is located here. While the API will accept both protected_branch_ids and applies_to_all_protected_branches, it will ignore protected_branch_ids if both are passed in, so the implementation in terraform should use ConflictsWith to prevent both attributes being passed in together.

Within the Create and Update methods, the attribute should be set into the Rule Options object (go-gitlab already supports this attribute). Within the Read method, the value should be ready from the response and set into the state file.

After that, one new test should be written confirming the ConflictsWith value works properly and returns an error if both attributes are populated, and one new test step in the basic test should be added ensuring the new attribute populates properly.

Additional Details

• GitLab Terraform Provider Version: v16.3.0
• GitLab Version: 16.3